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x86: Fix support for booting bzImage
[u-boot] / arch / i386 / lib / zimage.c
1 /*
2  * (C) Copyright 2002
3  * Daniel Engström, Omicron Ceti AB, daniel@omicron.se
4  *
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21  * MA 02111-1307 USA
22  */
23
24 /*
25  * Linux i386 zImage and bzImage loading
26  *
27  * based on the procdure described in
28  * linux/Documentation/i386/boot.txt
29  */
30
31 #include <common.h>
32 #include <asm/io.h>
33 #include <asm/ptrace.h>
34 #include <asm/zimage.h>
35 #include <asm/realmode.h>
36 #include <asm/byteorder.h>
37 #include <asm/bootparam.h>
38 #include <asm/ic/sc520.h>
39
40 /*
41  * Memory lay-out:
42  *
43  * relative to setup_base (which is 0x90000 currently)
44  *
45  *      0x0000-0x7FFF   Real mode kernel
46  *      0x8000-0x8FFF   Stack and heap
47  *      0x9000-0x90FF   Kernel command line
48  */
49 #define DEFAULT_SETUP_BASE  0x90000
50 #define COMMAND_LINE_OFFSET 0x9000
51 #define HEAP_END_OFFSET     0x8e00
52
53 #define COMMAND_LINE_SIZE   2048
54
55 static void build_command_line(char *command_line, int auto_boot)
56 {
57         char *env_command_line;
58
59         command_line[0] = '\0';
60
61         env_command_line =  getenv("bootargs");
62
63         /* set console= argument if we use a serial console */
64         if (NULL == strstr(env_command_line, "console=")) {
65                 if (0==strcmp(getenv("stdout"), "serial")) {
66
67                         /* We seem to use serial console */
68                         sprintf(command_line, "console=ttyS0,%s ",
69                                  getenv("baudrate"));
70                 }
71         }
72
73         if (auto_boot) {
74                 strcat(command_line, "auto ");
75         }
76
77         if (NULL != env_command_line) {
78                 strcat(command_line, env_command_line);
79         }
80
81
82         printf("Kernel command line: \"%s\"\n", command_line);
83 }
84
85 void *load_zimage(char *image, unsigned long kernel_size,
86                   unsigned long initrd_addr, unsigned long initrd_size,
87                   int auto_boot)
88 {
89         void *setup_base;
90         int setup_size;
91         int bootproto;
92         int big_image;
93         void *load_address;
94
95         struct setup_header *hdr = (struct setup_header *)(image + SETUP_SECTS_OFF);
96
97         setup_base = (void*)DEFAULT_SETUP_BASE; /* base address for real-mode segment */
98
99         if (KERNEL_MAGIC != hdr->boot_flag) {
100                 printf("Error: Invalid Boot Flag (found 0x%04x, expected 0x%04x)\n",
101                                 hdr->boot_flag, KERNEL_MAGIC);
102                 return 0;
103         } else {
104                 printf("Valid Boot Flag\n");
105         }
106
107         /* determine boot protocol version */
108         if (KERNEL_V2_MAGIC == hdr->header) {
109                 printf("Magic signature found\n");
110
111                 bootproto = hdr->version;
112         } else {
113                 /* Very old kernel */
114                 printf("Magic signature not found\n");
115                 bootproto = 0x0100;
116         }
117
118         /* determine size of setup */
119         if (0 == hdr->setup_sects) {
120                 printf("Setup Sectors = 0 (defaulting to 4)\n");
121                 setup_size = 5 * 512;
122         } else {
123                 setup_size = (hdr->setup_sects + 1) * 512;
124         }
125
126         printf("Setup Size = 0x%8.8lx\n", (ulong)setup_size);
127
128         if (setup_size > SETUP_MAX_SIZE) {
129                 printf("Error: Setup is too large (%d bytes)\n", setup_size);
130         }
131
132         /* Determine image type */
133         big_image = (bootproto >= 0x0200) && (hdr->loadflags & BIG_KERNEL_FLAG);
134
135         /* Determine load address */
136         load_address = (void*)(big_image ? BZIMAGE_LOAD_ADDR : ZIMAGE_LOAD_ADDR);
137
138         /* load setup */
139         printf("Moving Real-Mode Code to 0x%8.8lx (%d bytes)\n", (ulong)setup_base, setup_size);
140         memmove(setup_base, image, setup_size);
141
142         printf("Using boot protocol version %x.%02x\n",
143                (bootproto & 0xff00) >> 8, bootproto & 0xff);
144
145         if (bootproto == 0x0100) {
146
147                 *(u16*)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC;
148                 *(u16*)(setup_base + CMD_LINE_OFFSET_OFF) = COMMAND_LINE_OFFSET;
149
150                 /* A very old kernel MUST have its real-mode code
151                  * loaded at 0x90000 */
152
153                 if ((u32)setup_base != 0x90000) {
154                         /* Copy the real-mode kernel */
155                         memmove((void*)0x90000, setup_base, setup_size);
156                         /* Copy the command line */
157                         memmove((void*)0x99000, setup_base+COMMAND_LINE_OFFSET,
158                                COMMAND_LINE_SIZE);
159
160                         setup_base = (void*)0x90000;             /* Relocated */
161                 }
162
163                 /* It is recommended to clear memory up to the 32K mark */
164                 memset((void*)0x90000 + setup_size, 0, SETUP_MAX_SIZE-setup_size);
165         }
166
167         /* We are now setting up the real-mode version of the header */
168         hdr = (struct setup_header *)(setup_base + SETUP_SECTS_OFF);
169
170         if (bootproto >= 0x0200) {
171                 hdr->type_of_loader = 8;
172
173                 if (hdr->setup_sects >= 15)
174                         printf("Linux kernel version %s\n", (char *)
175                                         (setup_base + (hdr->kernel_version + 0x200)));
176                 else
177                         printf("Setup Sectors < 15 - Cannot print kernel version.\n");
178
179                 if (initrd_addr) {
180                         printf("Initial RAM disk at linear address 0x%08lx, size %ld bytes\n",
181                                initrd_addr, initrd_size);
182
183                         hdr->ramdisk_image = initrd_addr;
184                         hdr->ramdisk_size = initrd_size;
185                 }
186         }
187
188         if (bootproto >= 0x0201) {
189                 hdr->heap_end_ptr = HEAP_END_OFFSET;
190                 hdr->loadflags |= HEAP_FLAG;
191         }
192
193         if (bootproto >= 0x0202) {
194                 hdr->cmd_line_ptr = (u32)setup_base + COMMAND_LINE_OFFSET;
195         } else if (bootproto >= 0x0200) {
196
197                 *(u16*)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC;
198                 *(u16*)(setup_base + CMD_LINE_OFFSET_OFF) = COMMAND_LINE_OFFSET;
199
200                 hdr->setup_move_size = 0x9100;
201         }
202
203         if (bootproto >= 0x0204)
204                 kernel_size = hdr->syssize * 16;
205         else
206                 kernel_size -= setup_size;
207
208
209         if (big_image) {
210                 if ((kernel_size) > BZIMAGE_MAX_SIZE) {
211                         printf("Error: bzImage kernel too big! (size: %ld, max: %d)\n",
212                                kernel_size, BZIMAGE_MAX_SIZE);
213                         return 0;
214                 }
215
216         } else if ((kernel_size) > ZIMAGE_MAX_SIZE) {
217                 printf("Error: zImage kernel too big! (size: %ld, max: %d)\n",
218                        kernel_size, ZIMAGE_MAX_SIZE);
219                 return 0;
220         }
221
222         /* build command line at COMMAND_LINE_OFFSET */
223         build_command_line(setup_base + COMMAND_LINE_OFFSET, auto_boot);
224
225         printf("Loading %czImage at address 0x%08x (%ld bytes)\n", big_image ? 'b' : ' ',
226                (u32)load_address, kernel_size);
227
228
229         memmove(load_address, image + setup_size, kernel_size);
230
231         /* ready for booting */
232         return setup_base;
233 }
234
235 void boot_zimage(void *setup_base)
236 {
237         struct pt_regs regs;
238
239         memset(&regs, 0, sizeof(struct pt_regs));
240         regs.xds = (u32)setup_base >> 4;
241         regs.xes = regs.xds;
242         regs.xss = regs.xds;
243         regs.esp = 0x9000;
244         regs.eflags = 0;
245         enter_realmode(((u32)setup_base+SETUP_START_OFFSET)>>4, 0, &regs, &regs);
246 }
247
248 int do_zboot (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
249 {
250         void *base_ptr;
251         void *bzImage_addr;
252         ulong bzImage_size = 0;
253
254         disable_interrupts();
255
256         /* Setup board for maximum PC/AT Compatibility */
257         setup_pcat_compatibility();
258
259         /* argv[1] holds the address of the bzImage */
260         bzImage_addr = (void *)simple_strtoul(argv[1], NULL, 16);
261
262         if (argc == 3)
263                 bzImage_size = simple_strtoul(argv[2], NULL, 16);
264
265         /* Lets look for*/
266         base_ptr = load_zimage (bzImage_addr, bzImage_size, 0, 0, 0);
267
268         if (NULL == base_ptr) {
269                 printf ("## Kernel loading failed ...\n");
270         } else {
271                 printf ("## Transferring control to Linux (at address %08x) ...\n",
272                         (u32)base_ptr);
273
274                 /* we assume that the kernel is in place */
275                 printf("\nStarting kernel ...\n\n");
276
277                 boot_zimage(base_ptr);
278                 /* does not return */
279         }
280
281         return -1;
282 }
283
284 U_BOOT_CMD(
285         zboot, 3, 0,    do_zboot,
286         "Boot bzImage",
287         ""
288 );